/* Microsoft Reference Implementation for TPM 2.0
 *
 *  The copyright in this software is being made available under the BSD License,
 *  included below. This software may be subject to other third party and
 *  contributor rights, including patent rights, and no such rights are granted
 *  under this license.
 *
 *  Copyright (c) Microsoft Corporation
 *
 *  All rights reserved.
 *
 *  BSD License
 *
 *  Redistribution and use in source and binary forms, with or without modification,
 *  are permitted provided that the following conditions are met:
 *
 *  Redistributions of source code must retain the above copyright notice, this list
 *  of conditions and the following disclaimer.
 *
 *  Redistributions in binary form must reproduce the above copyright notice, this
 *  list of conditions and the following disclaimer in the documentation and/or
 *  other materials provided with the distribution.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ""AS IS""
 *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
 *  ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 *  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include "Tpm.h"

// This function is called to process a _TPM_Hash_Data indication.
/*
This indication from the TPM interface indicates arrival of one or more octets of data that are to be
included in the H-CRTM Event Sequence sequence context created by the _TPM_Hash_Start indication.
The context holds data for each hash algorithm for each PCR bank implemented on the TPM.
If no H-CRTM Event Sequence context exists, this indication is discarded and no other action is performed.

来自 TPM 接口的这一指示指示一个或多个八位字节数据的到达，这些数据将包含在由 _TPM_Hash_Start 指示创建的 H-CRTM 事件序列序列上下文中。
上下文保存在 TPM 上实现的每个 PCR 库的每个哈希算法的数据。
如果不存在 H-CRTM 事件序列上下文，则丢弃该指示并且不执行任何其他操作。
*/
LIB_EXPORT void
_TPM_Hash_Data(
    uint32_t         dataSize,      // IN: size of data to be extend
    unsigned char   *data           // IN: data buffer
    )
{
    UINT32           i;
    HASH_OBJECT     *hashObject;
    TPMI_DH_PCR      pcrHandle = TPMIsStarted()
        ? PCR_FIRST + DRTM_PCR : PCR_FIRST + HCRTM_PCR;

    // If there is no DRTM sequence object, then _TPM_Hash_Start
    // was not called so this function returns without doing
    // anything.
    if(g_DRTMHandle == TPM_RH_UNASSIGNED)
        return;

    hashObject = (HASH_OBJECT *)HandleToObject(g_DRTMHandle);
    pAssert(hashObject->attributes.eventSeq);

    // For each of the implemented hash algorithms, update the digest with the
    // data provided.
    for(i = 0; i < HASH_COUNT; i++)
    {
        // make sure that the PCR is implemented for this algorithm
        if(PcrIsAllocated(pcrHandle,
           hashObject->state.hashState[i].hashAlg))
            // Update sequence object
            CryptDigestUpdate(&hashObject->state.hashState[i], dataSize, data);
    }

    return;
}